NEUROANATOMY WEEK BY WEEK

Neuron

The basic unit of the nervous system responsible for transmitting nerve impulses.

Dendrites

Short, multiple projections from the neuron that receive signals from other neurons.

Axon

A long, single projection that transmits nerve impulses away from the cell body.

Myelin Sheath

A fatty insulation that speeds up signal conduction in neurons.

Cell Body (Soma)

Contains the nucleus and organelles; maintains neuron life and function.

Multipolar Neurons

Neurons with many projections; common in motor and interneuron functions.

Bipolar Neurons

Neurons with two processes; found in special sensory organs like the retina.

Unipolar Neurons

Neurons with a single process that splits into a 'T' shape; used by general sensory neurons.

Sensory Neurons (Afferent)

Neurons that carry signals to the CNS from sensory receptors.

Motor Neurons (Efferent)

Neurons that carry signals away from the CNS to effectors like muscles or glands.

Interneurons

Neurons that connect other neurons within the CNS; always multipolar.

Somatic Motor Pathway

A pathway controlling voluntary movement from the CNS to skeletal muscles.

Autonomic Nervous System (ANS)

Controls involuntary functions, including cardiac and smooth muscle, and glands.

General Visceral Efferent (GVE)

Autonomic fibers that provide motor control to visceral tissues.

General Visceral Afferent (GVA)

Sensory fibers that provide sensory input from internal organs.

Ventral Root

Contains motor fibers that carry signals away from the spinal cord.

Dorsal Root

Contains sensory fibers that carry signals towards the spinal cord.

Dermatome

An area of skin innervated by sensory fibers from a single spinal nerve.

Myotome

A muscle mass innervated by the motor fibers of a single spinal nerve.

Gray Matter

The central core of the spinal cord containing neuron cell bodies.

White Matter

Surrounds gray matter in the spinal cord; contains myelinated axons.

Cerebrospinal Fluid (CSF)

Fluid that cushions and protects the CNS, also involved in nutrient and waste transport.

Sympathetic Nervous System (SNS)

Part of the ANS that prepares the body for fight or flight responses.

Parasympathetic Nervous System

Part of the ANS responsible for rest and digest functions.

Thalamus

Relay center for all sensory pathways before reaching the cerebral cortex.

Cerebellum

Coordinates balance and fine-tunes motor actions.